The goal of the Biometrics Core is to provide investigators in this program project access biostatisticians who have experience with biostatistical methodology and their application to research in melanoma etiology and progression. The Biometrics Core staff will provide expertise in research methodologies necessary to design and implement rigorous experimental studies in Specific Aim 1. Through Specific Aim 2 they will provide expertise in informatics necessary to support efficient database development and database linkage, as well as expertise in statistical programming necessary for both descriptive and inferential statistical analyses. By way of Specific Aim 3 they will provide expertise in statistical methodology critical in the evaluation of research hypotheses and in the development of statistical models specified by the research objectives of each of the research projects. Through these specific aims the Biometrics Core will insure that this program project will have high quality study designs and statistical analysis plans that will provide a solid foundation for statistical inference.